This invention relates to a clamp construction especially useful for clamping a food mixer bowl in a stationary position on a bowl-supporting stand.
Food mixing equipment is often used in bakeries, restaurants and pizza shops for mixing ingredients used to make bread, cakes, pizzas, etc. A typical mixer comprises a vertical axis agitator (beater) adapted to extend downwardly into a circular bowl containing the ingredients to be mixed. The bowl is removably supported on a horizontal semi-circular arm structure. Two manually-operated clamp mechanisms are carried on the bowl for firmly holding the bowl in place on the supporting arm structure while the agitator is in operation.
Many of these mixing machines are equipped with timer devices for automatically controlling the agitation period. During the agitation period the equipment may remain unattended Therefore it is desirable to have a bowl-clamping mechanism that is very reliable and resistant to vibration forces associated with agitator operations.
A typical bowl-clamping mechanism comprises a rotary shaft having a clamping jaw thereon adapted to register with a rib projecting from the bowl. Manual rotation of the shaft in one direction causes the associated jaw to rotate around the shaft axis so as to overlie the rib on the bowl. Rotation of the shaft in the other direction causes the jaw to move away from the rib on the bowl, thereby enabling the bowl to be lifted off a stationary support structure underlying the rib.
The food mixer bowl has two external clamp mechanisms thereon at two diametrically spaced points on the bowl surface. Each clamp mechanism has its own operating handle. When the two handles are operated in the clamping direction the rotary clamping jaws are advanced to positions overlying the rib along opposite sides of the bowl, thereby locking the bowl in a fixed position on a bowl-support arm structure. When the two handles are operated in the reverse (unclamping) direction the clamping jaws are released from pressure engagement with the bowl rim.
These food mixers operate in an environment containing airborne particulates and liquids (e.g. flour, sugar, condiments, milk, water, etc.). Such materials can, overtime, migrate into the sliding interfaces within the bowl clamping mechanisms, thereby interfering with rotary motions of the mechanisms and in some cases shortening the service life of the equipment.
The present invention contemplates a novel lubrication system for the bowl clamping mechanisms. The lubrication system includes an arrangement of lubrication holes designed to produce an even distribution of grease onto different areas of the interface between each rotary shaft and the associated cylindrical bore in which the shaft is mounted. The preferred grease will be a grease material approved by the Food and Drug Administration for use in food processing equipment.